CINXE.COM

<!DOCTYPE html><html lang="en-US"><head><title>Just a moment...</title><meta http-equiv="Content-Type" content="text/html; charset=UTF-8"><meta http-equiv="X-UA-Compatible" content="IE=Edge"><meta name="robots" content="noindex,nofollow"><meta name="viewport" content="width=device-width,initial-scale=1"><style>*{box-sizing:border-box;margin:0;padding:0}html{line-height:1.15;-webkit-text-size-adjust:100%;color:#313131;font-family:system-ui,-apple-system,BlinkMacSystemFont,Segoe UI,Roboto,Helvetica Neue,Arial,Noto Sans,sans-serif,Apple Color Emoji,Segoe UI Emoji,Segoe UI Symbol,Noto Color Emoji}body{display:flex;flex-direction:column;height:100vh;min-height:100vh}.main-content{margin:8rem auto;max-width:60rem;padding-left:1.5rem}@media (width <= 720px){.main-content{margin-top:4rem}}.h2{font-size:1.5rem;font-weight:500;line-height:2.25rem}@media (width <= 720px){.h2{font-size:1.25rem;line-height:1.5rem}}#challenge-error-text{background-image:url(data:image/svg+xml;base64,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);background-repeat:no-repeat;background-size:contain;padding-left:34px}@media (prefers-color-scheme:dark){body{background-color:#222;color:#d9d9d9}}</style><meta http-equiv="refresh" content="120"></head><body class="no-js"><div class="main-wrapper" role="main"><div class="main-content"><noscript><div class="h2"><span id="challenge-error-text">Enable JavaScript and cookies to continue</span></div></noscript></div></div><script>(function(){window._cf_chl_opt={cvId: '3',cZone: "publications.waset.org",cType: 'non-interactive',cRay: '9135fc74498ef924',cH: 'YzSXgYPKx4zExnAGyUgCp1SljU_bMUDIbevDoc_9W3M-1739797497-1.2.1.1-mzbHAzHpVZDuKIxcjFqeTh6h9V9Jw3E_urtQs15VjHYTFKqT6DMoq3Wh7Q1fHMcm',cUPMDTk: "\/9680\/iso690?__cf_chl_tk=ofssk0_RNMuwMT_OhpE4hs90CfO7cyBkI2iT2W1gtOI-1739797497-1.0.1.1-hsQLH9miciVAYtTq678oOGM2_jNS2s3fczEKWS2Am8E",cFPWv: 'b',cITimeS: '1739797497',cTTimeMs: '1000',cMTimeMs: '120000',cTplC: 0,cTplV: 5,cTplB: 'cf',cK: "",fa: "\/9680\/iso690?__cf_chl_f_tk=ofssk0_RNMuwMT_OhpE4hs90CfO7cyBkI2iT2W1gtOI-1739797497-1.0.1.1-hsQLH9miciVAYtTq678oOGM2_jNS2s3fczEKWS2Am8E",md: "xioq_Gf5GkpyuJd3VFCMtUmRwmQnfkvjDgLZVSuub0A-1739797497-1.2.1.1-ynC7F4uuJZ3tmznwMYilrObfKYEFTH2rYkdu2o6QYZMM9o9gQcN8T7eR09QyFmWMvEdbpdmR85ghKQPyK859ImTAChLm6idP7HAYy3y5LsXgiC5yWKtUBLneKEYf.Hr9yqL6nfxeBt56ch0tdEzAyPzp_MsJfRaSBYSKwmhJsTB0pIV51ykc2qmjl1DiAvFIaMpSiLcLYV8c5e_c2BqPR6MQIWj0.OCCvqYtEytyEDtcHnyA1M3R5x5GvtdBtRi.9Px.NZtgzqqJaNPOAjQrdpXPxd5GSbHSV7MBI31pzYYXrNl0AMR54GTDMrM1mMaacNl6zQPxJs1BaVm5pFFpePTXQLveXySLEG_Zn8bXv.nPtpoPEvImU7.RWZhnTk0fiH1qpwLLE4ZCk4PaT.EWy5M5Xhhsm.VTNjmSRh17OmIM.s17o8yGg.PtNluhkgvISxdPFTLlpNjaDWXL5LvOYrgh6WHqAoLJPcYRdjOIAq1ILJ3D0DJWpZpUt.T9T8cl3zzcvAudODX2FPe8P2xVnvtfA0VVUMwmiPmbkz60cc9F8AZuYW12UwKMda60zu0nlZuPvxAaTRFRZhypnMLDrhvy_bNgST8hUoEUVidtX7Sw.TSSURbYVA_qmV2iB7b0ylcMEkxBgkKyaLvEzJb6GN_bQbcNvRZ4NJNmp7rUYNlKSDCo5WbGjNJZcY8AIVZIYkeC4MzbAwfzVxJI9KO1bSw5cFm2xeY2hFMeCW6jfZi9A_Xo5l7IcnZj5QMyfiJ5biFC2zO0aNvzFlbrU.9qRNM5K3sFVz29UpKYlKMxWzqEcJrvVV9nzTu.DxhsU7d6Ys5QIo18nI.BIP2YbSJ74GGD3ONipGsgaMF.C3z6OdlSo6rRd1bhphNxW45j0RNBdZ0tR4aUNphAlXYvNDLM110gLurLPcvubaNMiPOFIyyf2ohgZ_eIFvBPJ1egq5BDm_XceeodYZ4eBgFkCnW6ek7JjN3csxMiTd2qvBsVROY7D3RZ5lmaUytAFlfrY9fbWplyyj4yBswXxrc_sCsmAyPeVCpOBK980vxLdr2xMDh9qyLk3BVT3iz259foajy3XDxeqXvjI3WRysmSMJWhrZHFLBTSoXSFM6aYA.BHwJXl13xh7Rq369Yaa_TVdfmIhPpSGuwl8ulqNIjNN4cKbEBrQETxYtFgkM6l5u6oWOC7dYphmvn85Y63sf0vMknclHv1SM1Yfdk8hxa9TzdLCoKwMsr8SgezVkSvAIIVHft2ZjBcNuExqB08xFzOlFffTkHHUbn3yHd9u3yvj8Jw2gLinQQKP_KekK4WwpgjZUe.iRJvm0nb4E6go_gf3Qs_mBTL2JtRscXB01rPq7D6YjAbt1kEdhnagKLBTgKyWM_eFdo7Q8Qtvki8ObkV5uZX1ia2bRk8PbcWN.HzwHBJMLzf5yfnvUhKIKEXyE5c3H3xVlmjFzaiBa6jGle4CxeolCIYA__UG07PTw79czDIrLHL1joN3GfyuVLy2z5Zzz4XhOedGG25qXFkOYq5pNXkKBnvA3_Jv1CnoqWS2J7Mq9L5AaZgBM8Vc.3Q_djoHeyqMCbCTTxpB5dMd_QgOQuM5fl2JLd22VpHgHuIHfQ1ZDm08RluRzMV9ULXEAZeKrFxoyKI_.S64R1BvpUj6T_S3JOAmmtzMSHX_PxUamjU82Pm.d6IeI.6OwyZCAqapv96F7ulh4FCDrgcpeBfG0IfNG.K3XJ34Qt6htthSpC0ANXTq3xeDA61nRQNFljkQAsK7GWSgMjIt0Gd9O8iWhb8rWgB_2pyTAQKF.99Z2Ik9BqJwFAgr7QK_CcX6PvJVCCoORxRMDLlhYaUFzoQeb4_0f3rxhPX2oZ.7Nn6ddvE5Ca4wlE_DBhljShrlBJsoR8",mdrd: "U4Z3fKbDEtAyatgDg5OumCaFqdclqIgg93C1AnNW.9Q-1739797497-1.2.1.1-pVrmH.D8P8oW83w0TJg5k3xlFendxY8v303mfLdwxh_oYqHYZP69MiD1UJ6ewhLHIkiN3RxqHcWrynUfdC__tw7aT_L5z5hjoAqM7Xqg.GkRwbxI3cIaVRWKzhLSBVbtWJfJTVsZO4YQTx1Px4eQ9GicFjU7mmCfs_2AgnCfFYd7eLFZGIh9PwUcU_bmT.y4eppkhjYu1_ltuJ6B5u4_ROyiLZBOsqd_.ECLQ9uFkkqu5.7T8swwnqK4OmO.KN7u0IGxIGmcHCTKeJYcaZu4pWkVl5yDUEQryGj2BYB7oac5CNRfzd4E.k.L3WR05q8qnCX_zlmXL8gEfV7TWkJfy070jaQjkVORY3Sce8GlHvUO8Ih.qxez4bLMspyZ2RZd8.zhGp3tpWiswEU.w9uq0Yy8rgQHTwHvCuQ1EMwe2n1FjY78qsyWIfJcLRcl6N1LkbPzTMZvgna0Ssgsk5eMrs42rxObhgXncfrFzJN5fJMY2gW6cZHFKaPgyjBn92Jc9dQ2CZkcFfTHGWzmHWghvqQaLU_Sl1UpnBhMxzTLvaB_yWMCt1Zu5iXV5dCU8B52ZXs8TceAnjFUVUNbCNIdM.BOZICnV_Ewn8hXv4Zloe33vA4G0x1KlXab9g9rGlO5ibnvUlvTg6u85xDXMv6PN8zJbWgjvDCkyPsUQH5DiPvsvjevmf_rAP.LAGSpfFRBMgGYPjXfc8qNaGqAkdmg1PydrYiP7.nwEqPocboOa5oGSDoIEzvy8mEI3J4ED5Xoag0WrUEj.05.pLjOf3gvlMWxIpqV4O6oIg2WCzv7BG1bsbPM3i4bv9bemtQG195wHhh8cU8Nen5dyOutstTzJaI5X6IKBdybLsMN6IEuUpLz49bfIhPF9WGIE0v2dwnNcgTLIBQ3aXKp3.4_qvKvPDLb19JQvj6s1EG8KSyfanbRSWZthqq4iz7CvLgj4JGwO5sUtLaEFGjp5zbq6gBvC0v8jiSyRXWZCmbZoYLIFZPv8CRmvfHbJXxP9nf4An_EWXUggr8Kq.4oZ9bwhNbTKQ2sH1cPvvsdWIU7AxYbTODhGBp1ZJQlWG7F6jL3Whj0zkwL4bppkzIztD6licMweKYm7g8WByf.9wuQOtdYoVaNGMdJUSBT.G2dMtk.RiNPJx7W2U_Og4cxJM6yE4Gr0at_vRcSheoG39hO6z.0XVudT26xilTyxhq29hc81PqfRGLsF.m7bR1doo7tvf3ZNDbza1nFKJnvt6lgb6HMBK0StSlKpcKXTbTBTdf3F4065zRlEjKUVn.04mrC9Fyl6tvovtb.Xzo7AIew1dFt9.X7.F_Mpdv_TL6iHhYxmoQHl40BzjcBcTUBIbtT41N7UwdPz3YWjNbUgHy5ga8O5vFBxlLs4_E9XcrQq672XcnnBLuFtUN9d2tE7SCIuj_jSc8nVKyRZ9e7lnGpYGbsPbQV.y7ZuLUw145kT.PNOc2X4ELm32Q9sokWjMIykeTvZyeiUDMKpoaoLRy8qWI_kKkrqvCmaaGmHvkwNFYP8fEr3n_S2Q28gFhN1A24dr_Ut6Akden31tXvubq4sGbWA6.SrQuLq4eECjtD2eMS2PhKB2GHJ.CJ3LX.nD8It2LKjZpA8d2uFxlxJKSjdY7vtC4qb1MtGEaj.CDZmEcMlMBplevpQCs1UuSU61Qner32.tht0E55iqQJAhQxoFEuaSSpO46PNblS6jhhNPKyqzn1gpUUr2sTJWQB8.F3Nd3YYqvvWnMdplH.kIdQTiGpByeH36YCsr4JUOf7mPk9VX3TJsZPZkNJM6i8oTMoe47vMfDz2DbMF7tZUGCFgXqaocN1NYQ1YsT02e9EmyiC5kMy5yT0.Br_U8gQr.nsKbNdqQZ0fQBzoQs7C8.ESSSpwh5YsPPCBKXlXRUjc4BJfELV7yczsh8FnX1AF1.bPX_uPoRI6Y9nvdnYhD9z9.u0yjIlwFV.HchQAgqlLelTZhWV"};var cpo = document.createElement('script');cpo.src = '/cdn-cgi/challenge-platform/h/b/orchestrate/chl_page/v1?ray=9135fc74498ef924';window._cf_chl_opt.cOgUHash = location.hash === '' && location.href.indexOf('#') !== -1 ? '#' : location.hash;window._cf_chl_opt.cOgUQuery = location.search === '' && location.href.slice(0, location.href.length - window._cf_chl_opt.cOgUHash.length).indexOf('?') !== -1 ? '?' : location.search;if (window.history && window.history.replaceState) {var ogU = location.pathname + window._cf_chl_opt.cOgUQuery + window._cf_chl_opt.cOgUHash;history.replaceState(null, null, "\/9680\/iso690?__cf_chl_rt_tk=ofssk0_RNMuwMT_OhpE4hs90CfO7cyBkI2iT2W1gtOI-1739797497-1.0.1.1-hsQLH9miciVAYtTq678oOGM2_jNS2s3fczEKWS2Am8E" + window._cf_chl_opt.cOgUHash);cpo.onload = function() {history.replaceState(null, null, ogU);}}document.getElementsByTagName('head')[0].appendChild(cpo);}());</script></body></html>